摘要：分析了武汉地区武大和天虹2个采样点秋季灰霾和非灰霾天气细颗粒物PM2.5中的9种水溶性离子 (F^-、Cl^-、NO₃^-、SO₄^2-、Na⁺、NH₄⁺、K⁺、Mg^2+、Ca²⁺) 浓度。结果表明, NO₃^-、SO₄^2-和NH₄⁺是武汉秋季PM_2.5中最重要的3种水溶性离子, 且PM_2.5中各水溶性离子之间组成比例相对稳定;灰霾期PM_2.5中水溶性离子比例的增大是武汉秋季灰霾污染的重要特征, 它们可能来源于生物质燃烧、土壤扬尘、化石燃料燃烧、汽车尾气排放等过程, 其中天虹站点的大气二次污染比武大站点的严重, 固定源对武汉2个站点秋季灰霾期大气中NO_x与SO₂相对贡献均比非灰霾期的大, 移动源对天虹站点秋季大气中NO_x与SO₂的相对贡献则比武大站点的大。

关键词：灰霾;细颗粒物 (PM_2.5) ;水溶性离子

Abstract：Nine water-soluble ions of PM2.5 including F^-, Cl^-, NO₃^-, SO₄^2-, Na⁺, NH₄⁺, K⁺, Mg²⁺ and Ca²⁺ were analyzed during haze and non-haze periods in autumn at Wuda station and Tianhong station in Wuhan City.The results show that NO₃^-, SO₄^2- and NH₄⁺are the most important ions in PM_2.5 and the composition of the ions in PM_2.5is relatively stable. The increase of the proportion of water-soluble ions in PM_2.5 during the haze period is an important feature of the air pollution in autumn in Wuhan.They may be derived from the course of biomass burning, soil dust, combustion of fossil fuels, automobile exhaust emissions. The secondary air pollution in Tianhong station is more serious than that in Wuda station.The relative contribution of stationary sources to NO_x and SO₂ in Wuhan's atmosphere during the haze period is greater than that in the non-haze period. The relative contribution of mobile sources to NO_x and SO₂ in Tianhong station is greater than that in Wuda station.

Keywords：haze; fine particulate matter (PM_2.5) ; water-soluble ions